setPrompt(newPrompt) sets the Command Window prompt to the specified NEWPROMPT.
NEWPROMPT can be one of the following:

- a static string: setPrompt('>> ')
=> this is the default prompt string ('>> ')

- an evaluable string: setPrompt('datestr(now)')
=> the new prompt will look like: '25-Jan-2010 01:00:51'
Note: the evaluable string is expected to return a string

- an evaluable function: setPrompt(@()(['[',datestr(now),'] ']))
=> the new prompt will look like: '[25-Jan-2010 01:00:51] '
Note: the evaluable function is expected to return a string

- the static string 'timestamp' will continuously update the last (current)
prompt with the current time: '[25-Jan-2010 01:00:51] '. This has
the effect of displaying desktop command execution times.
The 'timestamp' string can be used with other static text to
customize its appearance. For example: setPrompt('<timestamp!> ').
- an empty value or no input argument restores the default prompt

Examples:
setPrompt('[-]') % Replaces '>> ' prompt with '[-]'
setPrompt('%') % => '% ' (space-padded)
setPrompt('sprintf(''<%f>'',now)') % => '<734163.056262>'
setPrompt('datestr(now)') % => '25-Jan-2010 01:00:51' (unchanging)
setPrompt('[''['',datestr(now),''] '']') % => '[25-Jan-2010 01:00:51] '
setPrompt(@()(['[',datestr(now),'] '])) % => '[25-Jan-2010 01:00:51] '
(note that these are the same: the first uses an evaluable string,
while the second uses an evaluable function)
setPrompt('timestamp') % => '[25-Jan-2010 01:00:51] ' (continuously-updated)
setPrompt('<timestamp> ') % => '<25-Jan-2010 01:00:51> ' (continuously-updated)
setPrompt('>> ') % restores the default prompt
setPrompt('') % restores the default prompt
setPrompt % restores the default prompt

Warning:
This code heavily relies on undocumented and unsupported Matlab functionality. It works on Matlab 7+, but use at your own risk!

Technical explanation:
A technical explanation of the code in this utility can be found on http://undocumentedmatlab.com/blog/setprompt-setting-matlab-desktop-prompt/

Bugs and suggestions:
Please send to Yair Altman (altmany at gmail dot com)